Vintage telephoto prime lens for Canonflex R-mount cameras.
The Canon R 135mm f/3.5 is a telephoto prime for the Canon R bayonet mount, produced for the Canonflex (1959) — Canon's first SLR camera and the first to use the Canon R mount. The Canon R mount was a proprietary bayonet that was subsequently superseded by the Canon FL and FD bayonets, making R-mount lenses the rarest and earliest of Canon's interchangeable SLR lens systems.
135mm focal length, f/3.5 maximum aperture, Canon R bayonet mount (Canonflex era, 1959–1964), manual focus, not compatible with Canon FD or EF bodies.
Canon R-mount lenses are the rarest of Canon's SLR lens families, produced only for the Canonflex and a small number of successor bodies. They are not compatible with Canon FL, FD, or EF bodies. A collector item representing the very beginning of Canon's SLR system development.
Verify this is the Canon R mount (not FL or FD) before use — the mounts are physically similar. Inspect for fungus, haze, and coating condition. Check aperture blades. Confirm Canon R bayonet engagement on a compatible Canonflex body.